All-plastic, non-rigid cryogenic container



1963 A. D. TRUBLE, JR 3,409,061

ALL-PLASTIC, NON-RIGID CRYOGENIC CONTAINER Original Filed Sept. 18, 19642 Sheets-$heet l 1968 A. D. STRUBLE, JR

ALL-PLASTIC, NON-RIGID CRYOGENIC CONTAINER 2 Sheets-Sheet Original FiledSept. 18, 1964 United States Patent ALL-PLASTIC, NON-RIGID CRYOGENIC'CONTAINER Arthur D. Struble, Jr., Torrance, Calif.

(2101 Rosita Place, Palos Verdes, Calif. 90274) Continuation ofapplication Ser. No. 397,436, Sept. 18, 1964. This application Mar. 6,1967, Ser. No. 621,068 2 Claims. (Cl. 150.5)

ABSTRACT OF THE DISCLOSURE This invention generally pertains to animproved container for cryogenic liquids and gases that can either beused in conjunction with apparatus such as a balloon, or for otherpurposes.

This application is a continuation of application Serial Number 397,436filed Sept. 18, 1964, now abandoned.

FIGURE 1 is a perspective view of a cryogenic container in accordancewith this invention;

FIGURE 2 is a cross sectional view of the cryogenic container shown inFIGURE 1;

FIGURE 3 is a perspective view of a multi-layer arrangement inaccordance with this invention;

FIGURE 4 is a side view of a multi-layer arrangement in accordance withthis invention;

FIGURE 5 is an alternative perspective view of a multi-layer arrangementin accordance with this invention;

FIGURE 6 is a perspective view of another embodimention of the inventionshowing the arrangement of strengthening members;

FIGURE 7 is a fragmentary perspective view of a multi-layer arrangementin accordance with this invention;'

FIGURE 9 is an end view showing a plurality of wound section;

FIGURES 8 and 10 are perspective views showing alternative embodimentsof wound s ctions in accordance with this invention. 1

In broad outline, FIGURE 1 shows an arrangement 3,409,061 Patented Nov.5, 1968 by a plurality of tie members 38 disposed at a plurality ofpoints around the circumference of each envelope.

It will be noted that on the lower side of the reservoir 20 a conduit 40is provided for withdrawing liquid material from the reservoir. Thisconduit 40 is controlled by a valve 42 that may be either manually orremotely controlled. The conduit preferably reverses itself (as shown atbend 44) so that when the valve 42 is turned topermit liquid to flowdownwardly into the reversed section 44 the liquid will reverse itsdirection and go upwardly through conduit leg 46. The liquid willusually turn to a gas as it rises upwardly in conduit leg 46. The gaspasses upwardly through conduit .leg 46, through conduit portion 51 andfinally into conduit 53, Conduit 50 is connected to the upper boil-offportion of the reservoir and the gas exiting through both conduit 50 andconduit 46 can be used to powera generator 52. The gas passing throughthe generator 52 can thereafter pass into conduit 55 and be used toinflate or to super-pressure a balloon 57. v The construction of theenvelope 22 is exceedingly important in accordance with this invention.It is not possible to simply use a thick solid layer of plastic materialsince a solid thick layer of plastic material will crack under stress atthe very low temperatures employed. In accordance with this invention,the envelope 22 consists of a plurality of layers of very thin plasticmaterial, such layers being attached together over only a very smallfraction of their abutting surface areas. There are a number of ways inwhich such a multi-laminate can be produced.

For example, FIGURE 3 illustrates an arrangement wherein there are fourlayers of very thin plastic material that have a thickness /5 mil orless and preferably a thickness of about mil. In this figure, it will beseen that betweenthe adjacent plastic layers 61, 62, 63 and 64 there areinterposed a plurality of spaced apart strength members S. The plasticsheets 61-64 may consists of polyethylene, Mylar, polypropylene or thelike and the strength members may consists of Dacron, Mylar, Nylon,polypropylene, polyethylene, Fiberglas or the like. The strength membersare preferably between about 15 and 30 denier. The, strength members Scan be arranged in a number of different ways and as shown in FIGURE 3comprising a cryogenic container 10, a lower cable 12 n leading to apayload 14, and an upper cable 16 leading to a balloon (not shown).

- FIGURE 2 is a cross-sectional view of the cryogenic container 10 shownin FIGURE 1. In FIGURE 2, a reservoir of cryogenic liquid (such asliquid hydrogen 20) is shown located within a generally sphericalenvelope 22. A bladder membrane 24 partially confines the reservoir ofliquid hydrogen and a gas under pressure is maintained within thechamber 26. The particular construction of the envelope 22 will bedescribed more fully hereinafter.

Surrounding envelope 22 are two .outer envelopes 28 and 30 respectively.Envelopes 28 and 30 are generally spherical and confine between them (i.in chambers 32) a gas under pressure.

The space 34 between the interior side of envelop'e 28 and the exteriorside of envelope 22 is maintained under conditions which are as near tovacuum as possible.

The envelope 22 is maintained approximately centrally within envelope 28by means of a plurality of supporting cables or struts 36. The outwardmovement of envelopes 28 and 30 with respect to each other is limitedalternating vertical groups of strength members are preferbaly disposedat right angles to each other. In the arrangement shown in FIGURE 3, theadjacent plastic layers 61-64 are either joined directly to each otherat spaced apart points or they are connected indirectly to each other byhaving each sheet connected to the strength members S that lie betweenthe sheets of thin plastic material. Connection may be by means ofadhesive, fusion, pressure welding, etc.

FIGURE 4 is a cross sectional view showing how the layers of material inFIGURE 3 could be joined together by spots of adhesives or heat fusionpoints A located at spaced apart intervals. It will be noted in FIGURE 4that.

the spots of adhesive are preferably not vertically aligned. It willalso be noted in FIGURE 4 that the fiber stringers or strength members Sare not actually joined to either of the adjacent plastic layers.However, they can be if so desired.

Referring now to FIGURE 5, it will be seen that in another arangementconsisting of four plies the strength members S are bonded directly tothe sheets and the sheets themselves do not need to be fused or adheredtogether in the manner shown in FIGURE 4. When using an arrangement suchas shown in FIGURE 5 it is preferably to heat-seal the sheets of plasticmaterial to both sides of the intervening strength members.

FIGURE 6 illustrates still another embodiment of the invention. In someinstances it may not be easy to bond the sheets of plastic material tothe intervening string-like strengtfimembers'due to the different natureof the materials involved. For instance, difficulties may be encounteredif the plastic sheet 68 is polyethylene and the strength members S areDacron. This problem can be solved by coating the Dacron fibers 69 witha polyethylene coating 70, and then bonding.

FIGURE 7 shows a multi-layer material which is particularly useful as aballoon envelope material 57 (see FIGURE 2).This multi-layer materialconsists of a layer of fabric material P (such as woven nylon) and alayer of neoprene N. The fabric material is porous but gives strength.The neoprene has little strength, but is quite effective in preventingthe escape of gas.

The cryogenic container described above is not radar reflective, whichmakes it quite useful in connection with military reconnaissance balloonsystems.

FIGURE 81O illustrate a novel piping construction which is particularlyuseful in connection with cryogenic liquids and with the invention shownin FIGURES 1-6. In the particular embodiment shown in FIGURE 8-10, thepipe consists of a plurality of concentric wound sections. Eachwoundsection is composed of strips of very thin, flexible material. Thestrips in each of the sections can be'identical or each of the stripscan differ in one or more respects. Each strip preferably consists of aplastic material, such as polyethylene, polypropylene, polyvinyl, nylon,Mylar, etc. However, at least one of the thin layers could be composedof metallic material, such as aluminum foil, tin foil, or the like. InFIGURES 8 and 9 an inner spirally wound inner section 80 is shown; whichis in turn surrounded by an intermediate spirally wound section 82;whichin turn is covered by an outer spirally wound section 84. The spiralsections are preferably wound in opposite directions relative to eachother in the manner shown, but this is not absolutely necessary.

The plurality of wound sections are preferably wound with varyingdegrees of tightness. For example, FIGURE 9 illustrates an embodimenthaving (a) a tightly wound inner core wherein the layers are partiallyor entirely fused to each other, (b) a relatively loosely woundintermediate section 88 and (c) and outer layer 90 that serves asa-protective strength cover. Each wrapped section can be composed ofnarrow strips of plastic having the same thickness, but the strips arepreferably of different thicknesses. Also the narrow strips of plasticcan be reinforced with thread members (composed of either textiles,plastic or metal). The plastic strips can also be coated with a thinlayer of plastic if desired.

As shown in FIGURE 10, the turns in each winding can be caused to adhereor bond to each other by means of an adhesive 99, or by thermal fusion,brazing, welding, etc.

Pipes constructed in the manner set forth above have superior qualitiescompared to conventional piping. After repeated use, pipes made of metalwill usually eventually crack, which means that they have a very limitedlife. In contrast, my piping provides excellent insulatingcharacteristics and excellent resistance to cracking even after repeateduse. When wound properly my pipe has sufficientstrength to make it quiterigid so that it can easily be made to support itself, plus handlinghigh hydrostatic or gaseous pressures. The ability of the pipe to expandand contract in the several layers relieves the thermal stress that arethe cause of thick-wall piping failures. The materials which I use havevery low cold brittleness characteristics and the bending stressesnormally associated with handling cryogenic materials are minimizedbecause of the very thin gauge material usedf I V What is claimed is:

1. An improved container comprising in combination:

(a) a walled reservoir adapted to contain a reservoir cryogenic liquid;Y

(b) said wall reservoir being surrounded by an inflated chamberconsisting of inner and outer ,Walls that have limited movement withrespect. to each other;

(e) the exterior of said walled reservoir. being positioned inwardlyfrom the-inner Wall of inflated chamber by spacing means; I

(d) the pressure between the outer side of said inner wall and the innerside of 'said outer wall of said inflated chamber being greater thanatmospheric;

(e) the pressure between the exterior side of said walled reservoir andthe interior side of the inner wall of said inflated chamber being lessthan atmospheric, and

(f) at least one opening in said wall reservoir for the passage ofcryogenic material. r

2. An improved container comprising in combination:

(a) a walled reservoir adapted to contain a reservoir cryogenic liquid,said walled reservoir comprising a multi-layer wall constructioncomprising:

(1) a plurality of sheets of plastic material;

(2) the thickness of said sheets being less than about /2 mil but notless than about mil;

(3) a plurality of thread-like strength members being interposed betweenadjacent sheets at spaced apart intervals;

(4) said sheets and said strength members being bonded together into aunited whole by spaced apart adhesion means;

(b) said walled reservoir being surrounded by an inflated chamberconsisting of inner and outer walls that have limited movement withrespect to each other;

(c) the exteriorof said walled reservoir being positioned inwardly fromthe inner wall of inflated chamber by spacing means;

(d) the pressure between the outer side of said inner wall and the innerside of said outer wall of said inflated chamber being greater thanatmospheric;

(e) the pressure between the exterior side of said walled reservoir andthe interior side of the inner wall of said inflated chamber being lessthan atmospheric; and

(f) at least one opening in said walled reservoir for the passage ofcryogenic material.

References Cited UNITED STATES PATENTS 2,028,670 1/1936 Hoshing 161-1482,030,746 2/1936 Gallinganetal 161-148 2,639,248 5/1953 Overholt 161-893,001,683 10/1961 Buckhold etal. 220 15 3,072,512 1/1963 Dalle 161-893,155,265 11/1963 Reese 220-15 FOREIGN PATENTS 1,273,907 9/1961 France.

WILLIAM T. DIXSON, JR., Primary Examiner. I. R. LECLAIR, Examiner.

